Gordon Cullen (1914-1994) was a key figure in 20th-century urban design. If Cullen’s contribution in promoting the Townscape’s Architectural Review agenda is well known, his career as a private consultant and his involvement in innumerable British redevelopment plans has not still been sufficiently investigated. Furthermore, his archive at the University of Westminster is almost entirely unstudied, leaving a significant gap in understanding his broader influence on urban development. This paper address this omission focusing on The Greater Peterborough City Plan (1971). The research employs archival investigation of Cullen’s reports, sketches, and drawings, alongside site visits, photographic documentation, and visual analysis of present day urban spaces. The findings highlight Cullen’s distinctive ability to capture lived experience through sequential sketches. His Peterborough project demonstrates that modernisation and new buildings can coexist with historic character, showing that urban development, when thoughtfully conceived, can reinforce a sense of place.